The proposal requests a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer to assist researchers at the Mount Sinai School of Medicine in the areas of protein identification/characterization and gene discovery/functional genomics. Currently, there is no MALDI-TOF instrument at the Mount Sinai School of Medicine, the fundamental reason for this request. The purchase of the Spectrometry Core Facility" at Mount Sinai and our recent recruitment of Dr. Yingming Zhao to head the facility. Dr. Zhao trained at the Rockefeller University with Dr. Brain Chait, one of the world's premier mass spectrometrists, and has published numerous papers describing mass spectrometry methodology development and the use of mass spectrometry (and specifically the MALDI-TOF) in a wide range of bioapplications. The establishment of this core facility and the purchase of the MALDI-TOF are essential to the continuing expansion and enhancement of the basic research programs on the Mount Sinai campus. As described in the application, 27 investigators from 6 different departments on campus have a specific need for this equipment. Indeed, due to the lack of a MALDI-TOF instrument on campus, some of these investigators are currently forced to collaborate or contract with other institutions or private companies to pursue their research goals, a situation which often results in long delays and hinders productivity. Thus, the purchase of the MALDI-TOF mass spectrometer, in conjunction with the recruitment of Dr. Zhao and establishment of the core facility, will have a major impact on research at our school.